Certainly it refers to the meal, but opinions differ as to whether teatime is 4-5 pm or 7-8 pm (what others call dinner or supper). I have never encountered 5-6 pm myself, but I suppose it's a reasonable compromise.
–
TimLymingtonApr 6 '12 at 16:27

I had always assumed that teatime was an early-afternoon sort of thing. So I learned something completely new today!
–
KChalouxApr 6 '12 at 17:00

5

@KChaloux - in the civilised northern reaches of England, Tea is the meal in the evening after work. Some of the denizens of lower-England insist on calling it dinner because they know no better. Dinner is at dinner-time in the middle of the day.
–
mgbApr 6 '12 at 18:16

The thickness of liquids in Pratchett's stories is often an issue. For instance, footprints in the river almost certainly will fill in after a while.
It is quite possible he did mean that the tea was so thick it could be eaten. It depends on context.
But I do not recall any particular scene where the tea was so thick.

Good observation. I don't think it is, in fact, the case with this particular phrase given the accepted answer above, but I hadn't considered it being an example of his ever-present subtle wordplay.
–
KChalouxApr 6 '12 at 18:22

Dinner is what Americans call lunch. Tea is the evening meal, consisting of a light menu with tea. Then of course there is High Tea which is an institution mainly reserved for hotels and such places where the drink is served with canapes and sandwiches.

That doesn’t seem right to me to say that dinner is what Americans call lunch. On (special) Sundays and other holidays like Christmas, the American meal progression is breakfast, dinner, and supper, but on normal days it’s breakfast, lunch, and dinner. The point is that dinner is a larger meal than lunch or supper.
–
tchristMay 25 '12 at 7:13